Natural Selection

Summary:

BEACON, also known as the Bureau of Enforcement, Armed Combat and Offensive Neutralization (it sure is offensive, Stiles thinks) has established the Avengers Initiative in order to, uh, fight crime. And rampaging alien hordes. And stuff.

Stiles is Iron Man. (Scott is Rhodey. Oh, Scott.)

Derek is the Hulk.

Lydia is Black Widow.

Allison is Hawkeye.

DANNY IS CAPTAIN AMERICA WHO EVERYONE LOVES.

Jaxon is a creepy alien dude with Daddy issues. And also Danny issues. Daddy Danny issues. Danny is justifiably alarmed.

Erica is Pepper Potts, except with more of an inclination toward bodily harm.

Chris Argent is the head of the Avengers Initiative. He is also fierce. He is also a silver fox. Hot damn.

And somehow, in the middle of all this chaos, the Hulk and Iron Man find love.

Notes:

Chapter Text

He's down in the lab, tinkering with a new alloy that should, theoretically, withstand anything from nuclear missiles to alien projectile-claws with paralytic poison in them (thanks, Jaxon), when the Hulk crashes in the door.

And prowls.

Stiles stands there, surrounded by several billion dollars' worth of classified technology, while the Hulk… prowls. Back and forth. Back and forth. And growls, and paws at the floor.

"Um," says Stiles. "Should I get a tranquilizer dart? Or two? Or a million?"

The Hulk snarls. Muscles ripple beneath his fur; his eyes burn, red as the flames of hell.

Stiles gulps. "Oh-kay, then. If you want to kill me, do it later, all right? I've gotta finish this prototype, or BEACON will be up my ass. And not in the fun way, either."

The Hulk huffs. Paws the floor some more. And keeps pacing.

Fine. Dr. Deaton had said that the best way to not get killed by a mutant werewolf was to not run from it, and a wussy freakout would kind of put a serious dent in Stiles's street cred. The Hulk will leave soon, anyway. He doesn't have a reason to stay. That, and Stiles has a panic button embedded in his freaking spinal cord. He can take a bit of terror. Terror's good for concentration. It provides focus. Like a lens.

The Hulk's claws leave gouges on the concrete.

Stiles just… lowers his visor, grabs his laser-cutter, and gets back to work.

He gets lost in it, as he always does, the near-silent hum of the arc reactor a pleasant companion to the constant buzz of his mind, equations flitting in and out of it like bright, metallic birds. He pulls up a few holo-screens and sketches them, quick as he can, darting between application and theory, molecular models glittering in silver lines.

At some point, he starts whistling, juggling a pair of pliers back and forth. At some other point, a cup of coffee materializes next to his elbow courtesy of a robot-hand - which he cheerfully shakes - and at some other-other-other point, the rumble of Stiles's stomach disrupts what he realizes is stream-of-consciousness dirty talk as he murmurs sweet nothings to his new alloy. Damn, she's pretty. And yes, she's a girl alloy. She's too pretty to be a boy alloy. Allison says gender stereotypes are stupid, which is a fair observation, since Danny's dimples are prettier than anything in the known universe, but still. This is one sexy alloy. It's the little black dress of metallurgy. The glorious lovechild of applied physics and chemistry. The -

"Sir," interrupts a botty voice. "You're hungry."

"Shove it," he says. "And I mean that literally."

Stiles opens his mouth, and freshly-replicated curly fries are summarily shoved into it.

He chews. Swallows. Spares a moment to close his eyes and make orgasm-noises, because the Cajun powder is to die for.

Thankfully, the botty voice and its annoying interruptions (except for the fries, damn, those can never be annoying) goes away.

He keeps working.

Danny is going to love this. It'll fortify his shield almost limitlessly, until no known threat can possibly put a crack in it, let alone destroy it. Modifying it to coat the fullerene nanogears in Stiles's own armor will be a slightly more complex task, but hey, complexity's his comfort zone. Complexity is to him what mojo is to Austin Powers. Yeah, baby, yeah.

Finally, at whatever o'clock, he's done.

Okay, he's never done-done, but at least he's followed one of his gazillion trains of thought to its more-or-less logical conclusion and has produced something that'll give BEACON a collective boner the size of the Eiffel Tower, so. He's done. (For now.)

As if magically sensing his return to the human world, Erica strolls in with a file in one hand and a stylus poised like a weapon in another. What few people know is that it is a weapon, and not just because Erica keeps stabbing him with it whenever he gets distracted during board meetings. It's also a mini-dart thrower and can release toxic gas into the face of whichever person offends Erica enough to deserve death. Which is practically everyone, eventually.

And now, it's Stiles. She's got that glower on her face.

God, she's going to insist he eats 'real food' again, isn't she? Curly fries are totally a valid food group; he's gotta change the FDA's stance on that. Maybe bribe a politician or two. Get a couple lobbyists in there. He can do that, can't he? It doesn't contradict the superhero moral code to manipulate national policies in one's favor, does it?

Damn it. It does. Stiles's inner Captain America (because Danny is everyone's conscience) is so disappointed in him right now.

But, surprisingly, Erica doesn't say anything about Stiles's deplorable eating habits and how they're going to kill him slowly, so she might as well do him the mercy of killing him quickly. (She and Lydia must have slumber parties in which they bond over the myriad ways to intimidate, interrogate and assassinate people. Allison probably brings cookies to these cozy get-togethers, which - in Stiles's imagination, at least - always result in lesbian threesomes. Very giggly lesbian threesomes. In silk pajamas. And then out of silk pajamas. Mm. And, yeah, maybe it'd all be more realistic with Allison and Lydia in matching black T-shirts with 'Budapest' printed on them in bloody scarlet, but Stiles prefers his fantasies.)

Instead, Erica points accusingly at a corner of the lab. The stylus glints. Like a knife. "What's that doing here?"

Stiles turns to look. "Huh?"

Oh. There's a -

There's a naked guy asleep in the corner of Stiles's lab.

A naked Derek.

A very naked Derek.

A very -

That's very -

Um.

"I can explain this," Stiles says, even though he can't, really. Had he seriously forgotten that there was a giant rage-monster in the same room as him? Is he actually as suicidal as BEACON's asshat psychologists say he is? "He just, uh. Came in here. And by 'came,' I mean entered, not - not jizzed, or anything. And by 'entered,' I mean - "

"Stiles. What is. He. Doing here."

"I don't know! How am I supposed to - "

Derek stirs. Groans. And settles, again.

Erica and Stiles glance at each other.

And back quietly out of the lab.

Very, very quietly.

Once they're out in the corridor, Erica grips his arm in a taloned hand (that isn't a manicure, it's a cat o' nine tails - well, five tails) and whispers: "What is the Hulk doing in your lab?"

"Uh. He's not the Hulk?"

"Don't give me that bullshit. It wasn't Derek Hale that walked into your lab. It was - "

"Yeah, fine, it was the Hulk. Whaddaya want me to say?"

"Why didn't you call someone?"

"What, his handlers? He's the Hulk. He doesn't have handlers. Largely because, oh, no one can handle him."

"Officially, BEACON are his handlers."

"Officially, BEACON are jerkoffs."

Erica stares at him.

Stiles runs a hand over his hair. "Look, just - we trust him to fight with us, right? We're supposed to be a team. I don't - I don't want to call BEACON every time he acts up or fails to cool down after a mission or, or. Gets angry."

"Yeah, but… his family was burned alive by his psycho ex-girlfriend and his uncle turned into a supervillain that genetically engineered himself and Derek to be crazy vengeance-seeking monsters, and then Derek had to kill his uncle who was also his only remaining relative, and… that'd give any guy anger management issues, wouldn't it? I don't want BEACON coming in here and shooting him full of sedatives like he's some kind of goddamn - "

"Animal? Killer? Guess what, Stiles, he's both."

"He doesn't kill our own!"

"He tried to kill Lydia last week."

"That was because she was possessed by a supervillain's ghost! And you know which supervillain!"

"He. Almost. Killed her."

"But he didn't! …After BEACON shot him full of sedatives, sure, but - "

Erica crosses her arms. And raises her eyebrows. Her stylus taps her elbow like a fucking metronome.

"Fine, relax, I get it. I shoulda called BEACON. Big deal. All he's doing right this second is sleeping."

"How the hell could he fall asleep in there? With all the hammering and whirring and you talking like a lunatic?"

"Hey, I talk like a sane person!"

"You talk to yourself."

"I talk to myself like a sane person!"

Erica snorts, and shoves the file into his arms. "Read that. And don't be late for the meeting."

"What meeting?"

"The one with Tarsus Pharmaceuticals, remember? The people working on healing serums? That you commissioned? By which I mean, I commissioned and you signed off on while nodding and pretending to pay attention?"

"I'll have some clothes sent up," Erica says, after watching Stiles stew in it for a couple minutes. Sadist. "He'll need to wear something, unless he enjoys nudity as much as a man as he does as a rabid wolf-creature. Not that his current body's half bad to look at…"

"Erica!" Stiles doesn't mean to sound like a scandalized grandma - or a scandalized chipmunk - but the indignant squeak escapes him, anyway.

"What? Not like you weren't checking that out."

"Nonsense. Sacrilege. Danny and Lydia are the only superheroes in my heart!"

"But not in your pants. Clearly."

"Stop mocking my lifestyle of absolutely voluntary chastity. That has nothing to do with my being unable to hook up with my godlike teammates or with human beings in general."

"Or aliens."

"Or aliens, yes, thanks for the Jaxon reminder. Like the venom still working its way out of my system isn't enough of a reminder to never flirt with Danny when Jaxon's within hearing distance or, uh, hissing distance - "

Erica pokes him in the back with her fingernails. She doesn't like being patronized. Well, tough fucking luck.

Derek's standing in the doorway, leaning against the jamb, completely nude. And completely unselfconscious, or at least, that's what it looks like, until he says: "Get me some clothes."

"Sure," says Stiles, and surreptitiously pushes Erica in the direction of anywhere-but-here. "I'll do that. Why don't you - would you like - coffee? Maybe?"

"Won't work on me. Metabolizes too fast."

"Of course. I - sorry, I. Maybe you'd like to… go back inside? For the time being? To prevent random passersby from pissing themselves in fear and/or creaming their pants in lust, because yes, those are generally the effects you have on people?"

Derek glares at him, dully, like he still isn't quite awake. And goes back inside.

"Wow." Stiles goggles. "It's been ages since I've even seen the Hulk's human side. Let alone talked to it. Him. I mean him."

"And yet you go out of your way to defend his honor and give him shelter," Erica drawls.

"I don't - "

"I'll send the clothes up. Oh, and remember to have food for dinner. Actual food. With actual nutrients. Which, for the record, do not include coolants or curly fries."

"Ha bloody ha," Stiles calls after her, as she turns and sashays away. Her hips are perfect sine curves. "The coolant thing was an accident! There was a bottle! It had a straw in it! I just -"

But Erica's just shaking her head as she leaves.

So. Back to his lab. Where a naked sometimes-monster is inexplicably waiting for him.

No. For clothes. For - for clothes. Yep. Not Stiles. Why would a naked sometimes-monster be waiting for Stiles?

Turns out, he is waiting for Stiles. If by 'waiting' one means 'stalking one back to one's lab and proceeding to terrify one out of one's wits.'

Much to Stiles's consternation, it's sort of become a thing. That Derek does. That the Hulk does.

This is how it pans out:

The Avengers go out for a mission; the Avengers come back to the mansion.

Black Widow typically heads up to her room to clean all the blood off her form-fitting latex outfit. Which is a process Stiles spends entirely too much time thinking about. Lydia is hot, okay? Especially when she's got that fresh-kill afterglow.

Captain America typically gets mobbed just outside the mansion, and fends off - or fails to fend off - overeager journalists with flashing cameras. Danny's way too chivalrous to turn down kiddy reporters from school newspapers, and ever since the media conglomerates realized this, the ages of the journalists approaching Captain America have been dropping steadily. Stiles fully expects to see a toddler waving a microphone, one of these days.

Hawkeye typically cleans her arrows with the sort of tender, pornographic attention that would give Scott a boner if he was ever around to witness it, which he's not, which is why she calls him up and they have phone sex, instead. Stiles only knows this because of that one time he is definitely not thinking about. Also, he does not want to know why Allison was giggling about bestiality. Just. No.

The Hulk… typically disappears to brood and claw pensively at wallhangings or whatever he does when he's in the middle of his angsty disappearing act, except that these days, his disappearing act is far less effective because it takes place in Stiles's lab. Where Stiles can see him. Not very effective, insofar as disappearances go. Stiles even considers finessing that nanobot invisibility cloak so that it'll hide the guy until Stiles is done with his work. Keep him out of sight, out of mind.

It's not even -

It doesn't make any sense.

Especially given the fact that when Derek is in Hulk mode, he's pretty much preverbal, so it's not like Stiles can talk to him. At him, sure. (Stiles does that a lot.) But not to him. Or with him.

And yet, somehow, in-between all the prowling and huffing and puffing, Derek… stays. As Stiles works. And falls asleep, right there, in a corner of Stiles's lab. Curled up like a - like a -

Like a very large, very muscular, very naked man-puppy.

Stiles is considering the pros and cons of a doggy basket. Pros: Doggy basket. For the Hulk. Heh. Cons: Getting killed by the Hulk. Possibly eviscerated. Hm.

It's a tough choice. In the end, though, Stiles opts for saving his neck, and doesn't get anything for Derek other than a collection of spare clothes, tailored specifically to fit his gargantuan shoulders. Those shoulders are like Mount Rushmore. Each one of Derek's shoulder-muscles is the president of its own small country with an obscenely high GDP. Jesus Christ.

Stiles just thinks it's the lab fumes. The Hulk must get high on lab fumes. Never mind that there are no fumes, because Stiles has sentient air purifiers that don't just purify the air, they analyze every kind of atmospheric emission from the radioactive to the yes-okay-boring. (Anything that isn't radioactive is boring, as far as emissions are concerned. Or as far as anything else is concerned. Let's face it; stable isotopes just aren't interesting.)

He - he gets used to it. Somehow. Beautiful machinery in his hands, beautiful not-always-rage-monster at his back. Maybe it's Stockholm Syndrome. Maybe it's a hostage situation gone… right. Wrong. So wrong that it's right.

Whatever the case, he and Derek seem to have an unwritten 'Don't Ask, Don't Tell' rule about it. Stiles very carefully doesn't ask what the hell Derek is doing here, and Derek shows no inclination of explaining his attachment to all things - lab. Lab, obviously. Not Stiles.

The rest of the team thinks it's hilarious, but they're too scared of the Hulk to bring it up in front of Derek, in case it makes him lose his temper. (Hah! That's an understatement; Derek doesn't lose his temper, he goes berserk.) So, naturally, the butt of all their puppy jokes and mating jokes (and, on one tasteless occasion, knotting jokes) is Stiles. Lydia takes a particularly malicious joy in pointing out that Iron Man can't pick up any girls, but has no trouble picking up stray mutant wolves. Haha. Very funny.

Danny is weirdly relieved, which is horrible, because a) it's not like Stiles was hitting on him that much, and b) it's not like Stiles and the Hulk are having some sort of exclusive relationship that precludes Stiles flirting with other people.

But no matter how much Stiles tries to explain that to other people, they still seem to worry about getting their heads ripped off, because they sort of go all… pale-faced when Stiles smiles at them or gives them casual compliments about their hair or their firearms. Even the one sweet-faced BEACON agent who'd tolerated him has started avoiding him, now, because she melts away like the world's prettiest ice cube when he's around. It's tragic.

He tries to whine to Scott about it, but Scott only snickers over the phone and repeatedly says the word 'bestiality'. In exactly the same tone Allison had said it.

Seriously. Those two. Stiles doesn't want to know what's going on in their heads.